The operation of the TOZO NC9 requires you to memorize the frame of mind of what it is supposed to do, not what it is supposed to do. Some commands are intuitive, such as one-tap on the right earpiece to play or pause audio, but others are a bit odd. After placing the left earpiece in the case, ANC is turned off when you take it out. (To turn ANC back on, you must turn the earphones on and off and restart ANC.) However, this does not actually work, so in effect, like the Bose QuietComfort 45 headphones, it will stay in either ANC mode or transparent mode. Here is what the NC9 is supposed to do The press-and-hold gesture feels longer than expected to adjust the volume, especially if you want to adjust more than one level at a time. Also, don’t try to adjust the volume on the NC9 during a call, or you risk losing the call. Complaints aside, at least you can tell which mode you are in because it will let you know audibly and you will hear a small beep indicating that a volume command has been registered. The TOZO NC9 Truly Wireless are well-made inner-ears with an impressive ANC feature that can block out ambient noise. The headphones have a V-shaped sound profile that adds extra oomph and punch to your audio, making vocals and lead instruments sparkle and shine. There is no dedicated ANC off feature, but the ‘Transparent Mode’ allows you to hear some ambient noise around you. Unfortunately, there is no ability to customize the sound to your liking, and they only last a little over four hours on a single charge. Fortunately, a portable charging case allows you to charge it three times while on the go. TOZO’s goal is to incorporate the latest science and technology, environmental materials, and fashion into its product designs to create unique, durable, and distinctive products. Compact and well-designed packaging is common to all TOZO earphones. Its materials are extremely clean, attractive, and totally lean, with plastic used only for the case that holds the silicone ear tips and for the thin outer wrapping.